A rare portrait of Queen Elizabeth I as a young princess has been discovered in a private collection at a stately home in Northamptonshire.
The portrait, dating from 1650 to 1680, was found in the Duke of Buccleuch's collection at Boughton House.
It shows Elizabeth with siblings Edward VI and Mary I, father Henry VIII and his jester, Will Somers.
It is a copy of an original panel painting, which is thought to date back to the early 1550s.
The portrait was examined by historians Alison Weir and Tracy Borman after they were told of its existence by the director of Boughton House.
It will now be put on display at the stately home, and historians hope to trace the original through publicising the discovery.
Portraits of Queen Elizabeth I before her accession to the throne are extremely rare, with only two other proven portraits known - one at Hampton Court and the other at Windsor Castle.
Tracy Borman said that when she was first sent a picture of the portrait she realised it had never been seen before.
"The more we found out, the more obvious it was that nobody had come across this," she said.
"It's clearly a copy of a lost original and it's that mystery that we started to try to solve.
"It's also a very different look to Elizabeth and comparing it to other portraits it helps us to solve the identity of other portraits - for example one always known as the Unknown Lady in the National Portrait Gallery."
Charles Lister, house manager at Boughton House, said the picture was to go on public display when the house opens in August.
He said: "The portrait is normally in a private area of the house with a number of other Tudor portraits.
"When we had a meeting with Tracy it came under discussion and it sort of all went from there.
"We knew it was important because it's a picture of Henry VIII and his family but we did not realise it in the context of Elizabeth as princess."
The finding is reported in the latest edition of the BBC History Magazine.